ME 4135 – Robotics and Control An Introduction

1. ME 4135 – Robotics and ControlAn Introduction Dr. Richard Lindeke 203 Engineering Building 726-7947; rlindek1@d.umn.edu

2. Outline • Some General Thoughts • uses and statistics • Project Management for automated Systems & Machines • What to consider • Working intelligently with the systems • The Overriding “Tenets of Automation” • Pose Control – Fixed Vs Flexible Automation • System Synchronization • System Balance • The Robot as a System – by definition! • Manipulator • Power System • Controller Schemes • End of Arm Tooling • Sensors (environmental)

3. Just Consider This: • Thank goodness robots are now at the point where using them is nearly the business equivalent of upgrading from a typewriter to a personal computer. Price has virtually been eliminated from the cost justification exercise. Today you get so much value in terms of software and technology, reliability and accuracy, that robots are affordable at any size. • Just as Joe Engelberger, the ‘‘Father of Robotics,’‘ has said so many times – when looking at solving manufacturing problems, ask the question: ‘‘Do you think a robot could …?’‘ It was a good question 40 years ago, and even better today with all the new technology.

4. Just Consider This: (from The British Automation & Robot Association) Search by [Automation/Robot] Application Area: Arc / Gas / Laser / Spot WeldingAssemblingBio-Chemistry and Hazardous ApplicationsCutting / Grinding / PolishingDispensing / Painting / Sealing / SprayingHandling Operations / Machine Tending / MouldingInspection / Measurement / TestingLaser / Water Jet CuttingLoading / UnloadingPackaging / Palletizing Search by [User] Industry: AerospaceAgriculture / Hunting / Forestry / FishingBasic Metals / Fabricated Metal ProductsBeverages / Food / Tobacco ProductsCeramicsChemicals / FuelsClocks / Medical / Optical / Precision / WatchesCommunications / Radio / TelevisionComputing / Electronics / SoftwareConstructionCork / Wood (excluding furniture)EducationElectric / Gas / Water SupplyFurnitureMinerals (non-metallic)Mining / QuarryingMotor VehiclesPaper / Printing / Publishing / Recorded MediaPharmaceuticalsPlastic / RubberResearch & DevelopmentTextiles

5. North American Robotics Companies Post Best Year Since 2007From: Robotic Industries Association(Posted 02/07/2011) • Ann Arbor, MI – North American based robotics companies reported strong growth in 2010, posting the best year since 2007, according to new statistics released by Robotic Industries Association (RIA), the industry’s trade group. • North American robot suppliers reported orders of 13,174 robots valued at $845.6 million from North American based companies, increases of 39% in units and 49% in dollars.  When orders from customers outside North America are included, the totals are 15,860 robots valued at $993.2 million, gains of 52% in units and 58% in dollars.

6. 2010 Robot Sales (U.S.A.) • The automotive industry, including OEMs and their suppliers, accounted for 51% of the North American orders in 2010.  Orders to this sector, the largest user in North America, were up 34% in units. • Non-automotive orders jumped 46%, fueled by large gains in orders from metalworking (+90%), semiconductor/electronics/photonics (+66%), plastics & rubber (+57%), food & consumer goods (+47%), and life sciences/pharmaceuticals/biomedical/medical devices (+26%).

7. Now in 2011 … • North American Robot Orders Jump 41% in First Half of 2011 • Robotic Industries Association Posted 07/29/2011 Second quarter is strongest quarter in six years: Fueled by its best quarter in six years, the North American robotics industry jumped 41% in the first half of 2011. • A total of 8879 robots valued at $577.8 million were ordered by North American companies in the first six months of the year.  When orders from outside North America are added, the totals are 10,476 robots valued at $667.9 million.  • The second quarter was particularly strong, posting gains of 50% in units and 55% in dollars over the same period in 2010.

8. U.S.A.’s Robotic Usage • RIA estimates that some 200,000 industrial robots are now used in the United States, placing the United States second only to Japan in overall robot use.  More than one million industrial robots are used worldwide.

9. Project Management for Automated Systems • Defining Automation: • Automation is the technology concerned with the application of complex mechanical, electronic and computer-based (computer-controlled) systems to the operation and control of production

10. Project Management for Automated Systems • Automation includes: • Automatic Machine Tools, Forges and Molders for workpiece processing (CNC & DNC) • Material Handling Equipment (ASRS’s, AGV’s, Reactive Conveyors) • Automated Assembly Machines • Feedback Control Systems/System Sensors • Process Controllers (PLC’s) • Automated Data Collection Systems (AIDC) • Automated Data Reporting Systems (MRP)

11. Project Management for Automated Systems – what to consider • The development of an Automated System is a 4 step process: • System problem analysis for overall needs • Determination of special needs • Design of control hierarchy • Building/programming of individual components

12. Working Intelligently with a Production System • Does Variety (types) or Piece Count (volume) dominate? • Consider Fixed Automation vs. Flexible Automation • Should we Consider Humans? • Typically, making it easier for automation makes it easier for humans (especially true for assembly) • Cost Justification of the system • Productivity Gains • Labor Replacement • Improved Quality, Repeatability & Reliability • Increased Production Capabilities • Quicker Changeovers

13. Project Management for Automated Systems – what to consider STEP 1 • Quantify Overall System Needs: • Number of Parts per hour (Production Rate!) • Product Variety • Part Size • Part Shape • Part Weight, etc

14. Project Management for Automated Systems – what to consider STEP 2 • Find Special Needs: • Robot Tooling and Machine Fixturing • Sensors for Pose Control or Decision-making • Communication Requirements (Machine to Machine)

15. Project Management for Automated Systems – what to consider STEP 3 • Determine Control Hierarchy: • Isolated Actions • Master/Slave(s) • Event Driven Response – under higher or parallel control

16. Project Management for Automated Systems – Final Actions STEP 4: • Build and/or Program Individual Units: • Robot Path Control • Machine Tool Codes • AGV Paths/Controls • ASRS Designs/Controls • Communication Network • Relays/Sensors, etc.

17. “Tenets of Automation”– Or what must be assured when Machines replace Humans Pose Control: is a principle that states that each degree of freedom of a machine, tool, product or process must be fully known or accounted for at all times for the (high quality) production systems to operate. Degree of Freedom is (in this physical sense): • a set of positional bits (X, Y or Z) • a set of Rotational bits (Roll, Pitch or Yaw) • Full POSE Control Requires 6 dof from the machine!

18. “Tenets of Automation” • System Synchronization (timing control) of operations must be maintained: • this requires that the sequence and timing of each movement during the process activity must be known and controlled. • This includes part counting, machine and product arrivals and departures, completed and closed communication sequences, etc.

19. “Tenets of Automation” • System Balance: • Each step in a process must be appropriately sized to complete its tasks within the overall system processing requirements. • Thus, no process should be slower/smaller (or faster/larger) than its predecessor or followers without accounting for product accumulation within the system.

20. Achieving Automation – Fixed vs Flexible • In Fixed Automation Systems • POSE CONTROL is imposed by stops, cams, rotators, etc • SYNCHRONIZATION is controller by in-feed supply, part feeders, hoppers, pallet movers, etc • BALANCE is controlled by (Overall System) design

21. Achieving Automation – Fixed vs Flexible • In Flexible Automation Systems • POSE CONTROL is achieve by sensing and adaptation by the machines and product in the system • SYNCHRONIZATION is by adapting to the changing needs of the feed stock and throughput demand • BALANCE is by design over extended time horizon, machines can be reprogrammed (on-line in Real Time) for changing part mix

22. The Robot System Contains 5 Major Sub-systems • Manipulator • Power System • Control • End-of-Arm Tooling • Environmental Sensors

23. The Robot System • The Manipulator – includes an Arm part and a Wrist part • consists of joints (revolute or prismatic), actuators, and kinesthetic (positional) sensors • Arm Types: • Cartesian • Cylindrical • Spherical • SCARA (selectively compliant assembly robots) • Articulating Arms

24. Cartesian Types (PPP) X0 Y0 Cantilevered Type Z0 J3 J2 J1 Gantry Type

25. Cylindrical Types (RPP or PRP) P-R-P//R-P-P Configuration

26. Spherical Types (RRP)  R Z0 Y0 X0

27. Articulating Type (RRR) Z0 3 L2 2 L1 X0 Y0 1

28. SCARA Type (RRRP)

29. Manipulator Wrists Spherical and/or RPY variants -- Idealized …To Practical Realizations of 3 dof Wrists

30. The Robot System • The Power Systems • Pneumatic for light loads at elevated speed • Hydraulic for heavy loads or very high speeds • Electric Servo for general applications

31. The Robot System • The Controllers • Bang-Bang: are mechanically programmed (movement to stops) and usually one-axis-at-a-time • Point-to-point servo: feedback of joints positions as moves from point A to B are run – no control of the path between A and B only end points are assured • Servo w/ Path Control: the motion is controlled completely between point pairs including positions and orientation to follow desired space curves • Autonomous Control: Device control that allows paths to be determined in ‘real time’ as the devices moves and interprets various sets of sensory inputs to create ‘intelligent’ paths as it moves

32. The Robot System • The End of Arm Tooling -- their complexity of task dictates the type of control scheme that is required • Grippers/Hands/spot welders • Sensor Arrays (static reading) • Sensors (active scanning) • Ladle/Hooks • Routers/Grinders/Drills • Spray Guns/Torches

33. The Robot System • Environmental Sensors • devices that give higher level information for program control and or path planning • Thus, Robots are Systems requiring design choices at 5.2 levels!